Electric motors and other electrical drive units are used in a variety of contexts. For example, some vehicles have one or more electric motors used for propelling the vehicle. Such motor(s) can be the vehicle's sole traction mode, as in a pure electric vehicle, or it/they can be used in combination with another traction mode, such as in a hybrid vehicle. In some vehicles, separate electric motors are used for driving respective front and rear axles.
The electric motor has a rotor and a stator, where the stator can be contained in part of a housing that also encloses a gearbox and in some cases other components. The process of manufacturing such motors can include a stage of closely fitting together a stator and a housing component, such as a cast aluminum part. In order to assemble the stator into its proper location inside the housing, it may be necessary to heat the cast housing so that its dimensions increase, and thereafter relatively quickly insert the stator component. Thereafter, the contraction as the housing cools down creates the close fit between the parts.